Improvement in desulphurizing ores and coal



UNITED STATES.

PATENT OFFICE.

WM. H. LETTERMAN, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN DESULPHURIZING ORES AND COAL.

Specification forming part of Letters Patent N 0. 28,875, dated June 26, 1860.

To all whom it may concern.-

Be it known that I, TILLIAM H. LETTER- MAN, of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented a new and useful Improvement in the Desulphurization of Coal and Metallic Ores; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawing, and to the letters of reference marked thereon.

The presence of sulphur in ore of various kinds is often a serious obstacle to obtaining the pure metal, and has consequently led to numerous processes of desulphurization; also, the presence of sulphur in many kinds of coal renders the latter unfit for usein manufacturing iron and for many other purposes.

My invention consists of an improved process of desulphurizing ore and coal in an efficient and economical manner. 3

In order to desulphurize ore or coal according to my process different kinds of apparatus may be employed; but as the apparatus forms no part of my invention a particular description of the same is not necessary.

The coal or ore, previous to being treated chemically, may be more or less broken or crushed, according to circumstances. If it be finely broken or crushed the chemical treatment is sooner completed; but in any case the process of desulphurization may be perfect.

The quantity of coal or ore operated upon at one time may vary according to circumstances or the scale upon which the business is to be conducted. Under ordinary circumstances I prefer to mix one ton of ore or coal with the following composition: chloride of sodium, (Na0l,) fifteen pounds; carbonate of potash, (KOOO +2HO,) one-quarter pound; nitrate of lead, (PbONO one-quarter pound; sulphate of soda, (NaOS03,) ne-half pound; nitrate of potash, (KONO one pound; protoxide of calcium, (quicklime,) ((JaO,) onequarter pound. The ore or coal mixed with this composition may be put into a suitable wooden box, tank, or chamber, which better be lined with lead or zinc to prevent the cor rosive action of the chemicals. This box or vessel is then closed with a tightl iitting cover or door, as the case may be. Now, in order to promote chemical action upon the ore or coal, heat and moisture must be supplied,-

completely removed, being carried off with the condensed steam. The acidulated water thus obtained from the condensed steam may be used a second time for thegeneration of steam,

.and the sulphuric acid present will facilitate the chemical action and the desulphurization of the coal or ore. Finally, the acid-water may be evaporated, and thus sulphuric acid will be obtained, often in sufiicient quantity to pay the expenses of the whole process of desulphurization.

Instead of using steam, as above described, some water may be put into the vessel with the ore or coal, and then heat may be applied directly to the vessel; or the chemicals may be placed in a separate vessel, through which steam is passed from the boiler to the ore in such a manner as to carry forward a small quantity of the chemicals with the steam, and thus impregnate and desulphurize the whole mass.

The amount and proportion of the aboveingredients and the details of the process may be somewhat varied, according to the kinds of ore or coal to be treated, without departing from my invention, so long as the process as a whole is substantially the same and produces the same effects.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent of the United States, is-

The above-described process of treating ore and coal with chemical ingredients and steam, substantially as set forth, for the purposes specified.

W. H. LETTE RMAN. 

